What are the New Ultra-low Nox Furnace Requirements in Colorado?

Starting in 2026, new Colorado regulations mandated by House Bill 23-1161 (HB23-1161) will require all new furnace installations and replacements to meet strict ultra-low NOx emissions limits of 14 ng/J. These standards are significantly more rigorous than current federal requirements and aim to reduce pollutants that contribute to ground-level ozone and smog.

It is important to note that these regulations apply only to new installations; your existing furnace is grandfathered in, and you are not required to replace a functioning unit simply because the rules are changing.

Enforcement Timelines

Compliance deadlines depend on your specific location within the Front Range:

• January 1, 2026: Enforcement begins for the Denver Metro area, Colorado Springs, and Castle Rock.
• July 1, 2026: Enforcement begins for all other areas across the Front Range.

Financial Incentives and Support

To help manage the transition, we offer Financing & Rebates assistance. Several utility providers offer incentives to offset the cost of compliant systems:

• Xcel Energy: Rebates up to $1,000.
• Colorado Springs Utilities: Rebates up to $800.
• Black Hills Energy: Rebates up to $600.

With over 15 years of Trusted Expertise, we can provide a HVAC system assessment to verify your current unit’s compliance and help you navigate the paperwork for available rebates. If you are planning a replacement, we will provide a custom quote for a high-efficiency, compliant model to ensure your home meets all 2026 state emissions rules.

• Colorado Furnace Regulations 2026: Essential Compliance Guide